1. Earthworm Dissection

2. Lumbricus terrestris Kingdom: Animalia Phylum: Annelida

3. Students should identify the following Segments Septum Setae Pharynx Esophagus Crop Gizzard Intestine Aortic Arches (Hearts) Ventral Nerve Cord Dorsal Blood Vessel Clitellum Seminal Vesicles Seminal Receptacles Cerebral Ganglion (brain) Anus Mouth

4. Students should know the following terminology Invertebrate Castings Hermaphroditic Hydrostatic Skeleton Closed Circulatory System

5. Before you start dissecting, find the following: Mouth Setae – the bristles used for locomotion. They are located by rubbing your fingers along the earthworm’s body. They are often times easier to feel than to see. Sperm Duct Clittelum

6. Mouth

7. Sperm Duct

8. Clittelum

9. Mouth Pin your worm at the tip of the mouth and at its anus.

10. Start your incision 2 cm behind the clittelum. Make sure not to cut too deeply!! Continue your cut to the mouth

11. Begin to separate the skin using pins

12. Pin the skin back as you go along the cut. Angle your pins outward so that are out of the way.

13. As you pin the skin back, take your probe and break the partitions between the segments. These are called Septum.

15. Pharynx

16. Aortic Arches – Earthworms have 5 pair of these simple hearts.

17. Aortic Arch

18. Seminal Vesicles

19. Seminal Receptacles

20. Crop

21. Gizzard

22. Dorsal Blood Vessel Intestine

23. Ventral Nerve Cord

25. Brain (Cerebral Ganglion)

26. Nerve Cord and Brain

27. Brain